I've heard "trying to perfect my _____" in common usage (western United States) quite a bit, usually with respect to specific narrow goals. It often has to do

I've heard "trying to perfect my _____" in common usage (western United States) quite a bit, usually with respect to specific narrow goals. It often has to do with cooking (perfecting a recipe), athletics (perfecting a maneuver), or games (perfecting a sequence of moves). The common thread is that there's a very specific problem with an attainable or near-attainable optimum. In contrast, "trying to improve my ________" seems to be used more with respect to general and broad goals. People speak of improving their marriage, improving their language proficiency, improving their work-related skills, and so on.